抄録
Nanostructures and optical properties of nanotechnology glass thin films containing Co3O4 were studied, and their applicability for optical recording media with high recording density was also investigated. The nanotechnology glass thin films were consisting of the Co3O4 grains with 10nm of average grain size surrounded by amorphous grain boundaries with 1nm thick. Their refractive index increased from 1.9 to 2.7 by laser beam irradiation at a wavelength of 405nm, and it decreased from 3.3 to 3.0 for λ=650nm. Absorption peak of Co3O4 thin film at 720nm was reduced and showed red shift indicating shifts of relative positions of ions by increasing temperature. The shift of positions of ions and band filling effect are the mechanisms of the large change of refractive index. Laser beam waist can be reduced to half, indicating that recording density of optical disk increases 4 times as much as that of current optical disks.
